import re;
def x(str):
	a=re.search(r'<meta.*name=[\'\"]keywords[\'\"].*/>',str,re.M|re.I);
	if(a):
		line=a.group();
		b=re.search(r'content=[\'\"](.*)?\"',line);
		if(b):
			return b.group(1).split(',');
		else:
			return '不存在';
	else:
		return '不存在';
str='''<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> 
<title>凤凰网</title> 
<meta content="凤凰,凤凰网,凤凰新媒体,凤凰卫视,凤凰卫视中文台,资讯台,电影台,欧洲台,美洲台,凤凰周刊,phoenix,phoenixtv" name='keywords' /> 
<meta name=“description” content="凤凰网是中国领先的综合门户网站，…"/>
<meta content="index,follow" name="robots"/> 
<meta content="凤凰网" name="author"/>
…
''';
print(x(str),"\n");

str2='''
<html><head><meta http-equiv="content-type" content="text/html;charset=utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=Edge">
<meta content="always" name="referrer">
<meta name="keywords" content="百度搜索,百度新闻,百度地图,百度视频,百度图片,百度贴吧,百度音乐,百度知道,百度文库,百度糯米"/> 
<link rel="dns-prefetch" href="//t12.baidu.com"/>
<link rel="dns-prefetch" href="//b1.bdstatic.com"/>
<title>百度一下，你就知道</title>  …
''';
print(x(str2),"\n");
print(x('sdfsdfd'));
